When I get my paycheck, money has already come off for health insurance. Do I need to give Maaser also for the money that came off for insurance? What about money that is taken off for taxes before I get the paycheck?
Regarding taxes- you give Maaser after deducting taxes.
Regarding health insurance- it would depend on the arrangement you have with your employer; if you can get this amount in cash or you can use it for any expenses as you wish, you must give Maaser from this amount as well.
If however it can only be used for health insurance (as is the case with some employers that are legally required to provide health insurance for their employees), Maaser is only given from the amount of the pay check.